Expect more risk of heatstrokes, asthma, allergies and infectious disease

It's a fair bet that global warming is going to lead to a rise in human sickness and death. But what form they will take is difficult to say. We can be pretty sure that as average temperatures climb, there will be more frequent and longer heat waves of the sort that contributed to the death of at least 20,000 Europeans in August 2003. Other predictions are more tenuous. For example, rising temperatures could--if rainfall and other conditions are right--result in larger mosquito populations at higher elevations in the tropics, which could in turn contribute to the spread of malaria, dengue...